A case involving a Hanover police officer could make it tougher for communities who don’t hire and promote candidates with top scores on Civil Service exams.

Hanover Patrol Officer Kristin Malloch filed a lawsuit after she was passed over for promotion to sergeant in 2012 despite the top score on the promotional exam. Two officers with lower scores were promoted.

Malloch has been a Hanover police officer for nine years. She was a Harvard University police officer before that.

In passing her over for promotion, the town cited a poor interview performance.

In a February ruling, Suffolk Superior Court Judge Paul Wilson said that state Civil Service officials have a legal obligation to review the reasons given by communities for not picking candidates with the top exam scores.

In 2009, Civil Service officials said appointing authorities, or communities, don’t have to send in their reasons for bypassing candidates, effectively allowing them to review their own decisions. The state officials cited budget restrictions as the reason for the change.

Wilson decided this doesn’t comply with the law.

“Where receive means review and approve, it is illogical for the statutory scheme to allow the town to review and approve its own statement of reasons,” Wilson wrote in the decision.

He referred the case back to the town and the state Civil Service Commission and Human Resources Division for action.

The state attorney general’s office has filed a notice of its intention to ask the state appeals court to overturn Wilson’s decision on behalf of the Civil Service Commission and the town.

Marshfield lawyer Frank McGee, who represents Malloch, said the decision could impact a large number of promotions made over the past few years.

“To put the town in a position to review its reasons for bypass is just absurd,” McGee said. “Civil Service is designed to create a level playing field.”

Hanover Town Manager Troy Clarkson, who made the final decision on the promotions, noted that the decision did not find any wrongdoing on the town’s part.

A spokesman for the attorney general’s office referred questions on the case to the Civil Service Commission and Human Resources Division.